Safety device for grinding machines



Oct. 6, 1931. H. E. BALSIGER 1,826,445

SAFETY DEVICE FOR GRINDING MACHINES Filed June 13, 1928 2 Sheets-Sheet 1IN V EN TOR.

MEOLD E. EELS/GER.

BY W A TORNEYS Oct. 6, 1931. H. E. BALSIGER 1,826,445

SAFETY DEVICE FOR GRINDING MACHINES Filed June 15, 1928' 2 Sheets-Sheet2 INVEN TOR. H/IQOLD E. BflLS/CDE ATTORNEYS.

I P a tentecl' Oct. 6, 1931 S ATE PATENT "OFFI I nimonnn. nALsIGnnQOrwAYnn'sBOno, PENNSYLVANIA, Assreivon ro nannis TOOL COMPANY, OF.wavnnsnono, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA 1 ssrn'rv nnvrcsRon 7 I 7 Application fled sums,

I This invention relatesto safety devices for use with anhydraulicallyoperated work rest 'on grinding machines, and particularly crankgrinding machines.

Itisan 'object'of the invention/to provide I a safety means whereby thework carriage on the grinding rmachine cannotz. be traversed the work.no

I. While. the work rest-is imposition .to support A furtherlobject isto' provide safety combination of'the' above character, an automaticpressure operatedxfiuid-by-passvalve.

A further generalobject istoprovidela 'fsafetydevice-in grindingmachines Orthe like to themachine;

which will require as little attention from an operator. as possiblewithout danger of injury Further. objects advantages. be;

7 come apparent. as" the description proceeds.

; 7. Referring to. the accompanying drawings,

' I which are-made apart hereof and on which jthegby-pass valve; and; y12 Figure 3 'isa sectional elev similarreference characters indicatesimilar I parts ure 25 v;

llis a partial end elevation; partly in sectioniof acrank grinderequipped vwith a stationary hydraulic back rest, and showing I the,safety device its relation to the ;grinder,

2-is asectional front elevation tionlof the pisvitoii;which operates thework rest.

The crankgrinding machine of which liniusntion is here shown as formingapart, is g the machine described in a co-pending application of AmosRsteiner, Paul Stonerand "Charles P. Harrison, s;erial No.126,583,'fi1ed August 2, 1 926, for crank grinding machines,

' jandythe back rest is that described in the application of Amos P.Steiner and Harold E.

Balsiger, Serial No. 143,248, filed October 21,

- V 1926; for jhydraulic back rests for grinding "machines The grindingmachine; and the back rest will therefore be described only insofa'r'asis'necessary to understand the'appli- 'cationof 'the' control device tothese machines.

f Intherdrawings numeral 10 indicates the base of a grinding machinehaving a travers- -abltarriage11 slidably mounted'in suitable,-1guideways thereon. Thetraverse-carriage is GRINDING. rmonnvns 1928.,Serial in. 285,113.

reciprocated by means of a rack 12 mountedthereunder, which is driven bya suitablepinion 13 which pinion is operated bym eans of an oscillatingmotor 14. The motor is driven by pressure fluid delivered theretothrougha pipe 15. The work 16 is mounted in a *well' known way upon thetraverse carriage in p0 sition to be moved to grinding position beforean abrasive wheel 17. The work rest (1011-, 'sists of a back restbracket'18, secured upon the-base of the machine, A slidable member 19carrying a Work engaging jaw 20 is moved toward and from workingposition by means of a pinion 21 engaging the rack teeth 22- on thelower part of the slide 19. 7 A small pinion 23 is connected to thelarge pinion 21 and is driven by means of rackteeth 24: on a piston rod25. The piston rod carries on its lower end a piston 26which moves in acylinder27.

sages to, the cylinder 27.. A reversing valve 30'admits pressure fluidselectively below or above the piston 26 to move the work engaging vjawlto operative position, or withdraw it from operative position. A lowerwork engaging jaw 31 ispivoted at 32 and is moved to operative positionby means of a plunger 33 which is connected to a plate 34 secured totheback rest slide-19. The details of the re versing valve 30have notbeen shown because any conventional structure for admitting fluid aboveand below piston 26 and for exhausting fluid from the cylinder 27 beused.

Connected with a chamber above-the pis- 7 ton 26 in the cylinder 27 is apipe35. This pipeconnects with a by-pass valve shown as a whole at 36,and which forms the control or safety feature of the invention. Thedetails of this valve will now be described:

I The valve comprises a valve casing37 having'a double piston 38 and 39reciprocably mounted in a bore therein. The piston 39 is longer than thepiston 38, and is provided with a flange 40 which engages a shoulder inthe cylinder valve body to limit the movement of the valve in onedirection. A cap 41 is screwed intothe end of the valve casing and has ahole 42 therethrough, into which is threaded a-connection on the pipe35. A53

shown in Figure '2. one end of the bore in the casing 37. This A cap 45'closes] {cap haswan adjiisting screw 46 threaded ii 'spring43. The valvecasing is pr ovided'with therethrongh and engaging the disc 44 toprovide means for adjusting the tension of the nl t police andadischarge PQ'IH A.

I pipe 49 conne'ets the dischargefport with suitable connectionsleading. toythe reservoir in the base of the grinding machine, notshown,

; 15 I I byjmeans' of ashort'pipe 51 wi'th the'pipelt') 'whichfsuppliesmotive fluid to'the oscillating A relief port provides-for leakag'e offluid past the piston 38, ,The port 4'1 is connected motor "*T eitensionofthe $Pring43is su'clithat it requires greater pressureto operatetheby-pa'ss valve'than the work resti I The valve will therefore 'no'tbe operated while thebackrest isbeing withdrawn','n or ti t e Pi tQ ihQew ey .lwer q t I 'o'sition. j

I Pv H, r

" The operation of thef deviee as z" 7 hen the piston 26 isjinthefabove. position .shown in fnll lines in Figure 1, thefchamber abovethefpiston is open to the high pressure withthe high pressure fluidChamber delivers shown in Eigiire against .the tension'of the spring43.: Thislfho'lds'the plnn'gerin'the position shown in full lines 'inFigure 2, and

I elosesjoommunication; between theipor't-s 47 I and 48." High pressurefinid in the pipe line 1 5 will thereforeb e delivered"t6 the osoillating. motor to drive the traversing earri'a'ge 11. Whe mjhowever'," thereversing velveso has'beef'n moved to admit high 1 pressure fluid tomove the back rest toioperzttive pes i;

ition inglengagement with theflwork 16, ;as s own i d t d, l s Fig re aWhen i below the piston26 andto exhaust itfabioye the'piston 2 6, thepistonfwill be' moved; up-

I the reversing, valve in this position, pres} sure fluid is" allowed toexhaust through the L jatjtheriglit of theflange'40' an 'the'piston .39

i and allows the spring143 to move the pistonto' reversible valve 3O tthepipe' 29. This shift ing of the reversing valve .relieves pressure 1the position shown'in dotted lines in 'Eignre 2.

, to traverse the work earriage, while the sta- -;:High pressure fiu'id"from the pressnre :lines 15 will then escape" thro igh the pipe 5-1,the

enders tionary back rest is in a position to support.

the! work. ril advantagesl'oi the device in" contributing a step'towardmakinga' machine it will be obvionsto those skilled in the art thatvarious changes may be'made in my device withoutdeparting from the;spirit'of the invention, and I, therefore, do not limit myself to whatis shown in the drawings and d ed n h Specification,-bnt-onlya t forthin thefappnded'claims:

r Having thus fully described my said inwh eel,means for reeiprocatingthe work oar-- ria'ge,means formoving the work rest to and fromoperative position, and means; con trolled by the movement "of said workrest to render the said carriage reoiprocating'means operativeoninoperative, substantially as {set forth.

2. n a, grinding families were hy drama-any operated workrest and ahydranlically traversed work carriage, means" for traversing the workCarriage, and means icontrolle bv movement of the wo kjestfer yen:

dering the said traversing imeans j oper'ative o .o o i n ti eisv s niall 'as Serena; ff fln d l ne 28; The p pe 35 in eommumc'ation I '7 f sm-thr ugh thepassag '4 i fiih s ,end of thelpiston'39ito force.it'tofthe'left, as

8. "In, afgrinding'mfi ihine a worlijearriage',

as set forth. i

" In grinding h n avbrkearfia'el,

a motor for traversing said carriagedahigh pressure motive fluid line,connected I to Y said m by-We ral e' sa d' nei'e' iverk rest, hydraulicmea'nsifor moving said back rest into and ont of onerative position, andconnections from saidp'hvdraiilie' Ineans to said by-pass whereby 'hypassgwilh be opened when saidwork rest is {in operative work e ei ispefitidng S t nt al y as forth. a 7 e H 5. 'In'combin'ation ing ahydranlieally operated workjrest," a

hydranlic carriageltraverse, and. interconnected means to preventtraversal of the work carriage when'therwork rest is either motionor isin operative poos'ition,substantiallv I "as setforthi. ports 47, 48 and,outletpassage 49, toa reserv oir in'thebase ofthe maehine. Thisrelieves thepres'sure in thepipe line 15 and r the traversing motor 14inoperative." This 60 provides asafetyagainst accidental attemptshydraulically operated, {carriage traverse,- a

work rest, fluid" connection fromsaid work a grindinginac'hine 11537 rIn combination ca?grindingjmaehiiie, a v

rest to said by pass valve whereby-said byv morenearly fool-proofshouldib'eapparent. pass' will open whenthe pressur'eis re'leased' ononeside of the pistonpsubstantially as set forth.

7 .In combination a grinding machine, a

hydraulically operated carriage traverse, a

source of pressure fluid, a by-pass valve in the pressure line betweensaid traverse opera ating means and saidsource of pressure, a-Vrfluidpressure operated piston for operating the Work rest,fluidconnection from said Work rest to said by-pass valve, Wherebysaid'by-pass will close when pressure is exerted ;1 on one side of thepiston, substantially as set 'forth.

7 t 8. Ina" grinding machine a hydraulically I, operated work rest,aihydraulically operated r carriage traversing mechanism, a high pres- 7sure fluid line froma source of pressure fluid for operating the saidWork rest and the said traversing mechanism, a by-pass valve in saidhigh pressure fluid line, a connection between the said Work rest andthe said valve whereby pressure fluid is directedto the carriage trav- 41 ersing mechanism orjis by-passed from the v a high-pressure fluid linedepending on the position of the Work rest, substantially as set v Iforth. r

I In Witness whereof, I have hereunto. set 'my hand at Waynesbo'ro this8th day of J U116, 33" D. nineteen hundred and'twentv eight.

HAROLD, E; BALVSIGER;

